Square vs non-Square Textures

Unity Engine
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1

I’m using Unity Pro with iPhone advanced.
I know that PVR compression requires power of two textures.

I want to know if there is a significant performance increase for using square textures instead of non-square textures.

Google searching showed two different opinions on this:

  1. People said it made no difference.
  2. People said that a non-square texture was “padded” up to a square texture in memory and resulted in more memory usage.
2

there is almost no performance increase to using pvr textures on 3gs and above. However there is a really sexy memory gain from using them. They are really tiny in ram.

They are technically faster than using uncompressed textures, but only if memory bandwidth is a problem (and usually fill rate and something else will be a problem before then). The use of mip mapping helps in all counts with situations like this as well.

So you probably won’t actually see a performance gain.

As is customary for me to mention: once unity decides to put texture streaming in iOS, mem bandwidth will probably be much more stable since instead of holding all the textures, you only have some of the textures to transfer… it should in theory be a bit quicker still for really large open world scenes.